Implementations of NMI watchdogs that use a single piece of hardware to
monitor all the CPUs in the system (as opposed to per-CPU implementations
such as perf) need to know which CPUs the watchdog is allowed to monitor.
In this manner, non-maskable interrupts are directed only to the monitored
CPUs.
Cc: Ashok Raj <ashok....@intel.com>
Cc: Andi Kleen <andi.kl...@intel.com>
Cc: Tony Luck <tony.l...@intel.com>
Cc: Borislav Petkov <b...@suse.de>
Cc: Jacob Pan <jacob.jun....@intel.com>
Cc: "Rafael J. Wysocki" <rafael.j.wyso...@intel.com>
Cc: Don Zickus <dzic...@redhat.com>
Cc: Nicholas Piggin <npig...@gmail.com>
Cc: Michael Ellerman <m...@ellerman.id.au>
Cc: Frederic Weisbecker <frede...@kernel.org>
Cc: Alexei Starovoitov <a...@kernel.org>
Cc: Babu Moger <babu.mo...@oracle.com>
Cc: Paul Mackerras <pau...@samba.org>
Cc: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
Cc: Masami Hiramatsu <mhira...@kernel.org>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Andrew Morton <a...@linux-foundation.org>
Cc: Philippe Ombredanne <pombreda...@nexb.com>
Cc: Colin Ian King <colin.k...@canonical.com>
Cc: Byungchul Park <byungchul.p...@lge.com>
Cc: "Paul E. McKenney" <paul...@linux.vnet.ibm.com>
Cc: "Luis R. Rodriguez" <mcg...@kernel.org>
Cc: Waiman Long <long...@redhat.com>
Cc: Josh Poimboeuf <jpoim...@redhat.com>
Cc: Randy Dunlap <rdun...@infradead.org>
Cc: Davidlohr Bueso <d...@stgolabs.net>
Cc: Christoffer Dall <cd...@linaro.org>
Cc: Marc Zyngier <marc.zyng...@arm.com>
Cc: Kai-Heng Feng <kai.heng.f...@canonical.com>
Cc: Konrad Rzeszutek Wilk <konrad.w...@oracle.com>
Cc: David Rientjes <rient...@google.com>
Cc: "Ravi V. Shankar" <ravi.v.shan...@intel.com>
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Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org>
Cc: io...@lists.linux-foundation.org
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Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Ricardo Neri <ricardo.neri-calde...@linux.intel.com>
---
include/linux/nmi.h | 1 +
kernel/watchdog.c | 7 ++++++-
2 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/include/linux/nmi.h b/include/linux/nmi.h
index e61b441..e608762 100644
--- a/include/linux/nmi.h
+++ b/include/linux/nmi.h
@@ -77,6 +77,7 @@ static inline void reset_hung_task_detector(void) { }
#if defined(CONFIG_HARDLOCKUP_DETECTOR)
extern void hardlockup_detector_disable(void);
+extern struct cpumask *watchdog_get_allowed_cpumask(void);
extern unsigned int hardlockup_panic;
#else
static inline void hardlockup_detector_disable(void) {}
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 5057376..b94bbe3 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -50,7 +50,7 @@ int __read_mostly nmi_watchdog_available;
static struct nmi_watchdog_ops *nmi_wd_ops;
-struct cpumask watchdog_allowed_mask __read_mostly;
+static struct cpumask watchdog_allowed_mask __read_mostly;
struct cpumask watchdog_cpumask __read_mostly;
unsigned long *watchdog_cpumask_bits = cpumask_bits(&watchdog_cpumask);
@@ -98,6 +98,11 @@ static int __init hardlockup_all_cpu_backtrace_setup(char
*str)
}
__setup("hardlockup_all_cpu_backtrace=", hardlockup_all_cpu_backtrace_setup);
# endif /* CONFIG_SMP */
+
+struct cpumask *watchdog_get_allowed_cpumask(void)
+{
+ return &watchdog_allowed_mask;
+}
#endif /* CONFIG_HARDLOCKUP_DETECTOR */
/*
--
2.7.4
